interactive

FlowFiled.pde

@@ -0,0 +1,91 @@
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileReader;
+import java.io.FileWriter;
+import java.io.IOException;
+
+class FlowField {
+  PVector[][] field;
+  int cols, rows;
+  int resolution;
+  int affectRadius;
+  File file = new File(dataPath("field.txt"));
+
+  FlowField(int r) {
+    resolution = r;
+    cols = 1200 / resolution;
+    rows = 950 / resolution;
+    field = new PVector[cols][rows];
+    init();
+    affectRadius = 3;
+  }
+
+  void init() {
+    try { readField(); }
+    catch(Exception e) {
+      for (int i=0; i<cols; i++) {
+        for (int j=0; j<rows; j++) {
+          field[i][j] = new PVector(0, 0);
+        }
+      }
+    }
+  }
+
+  PVector lookup(float x, float y) {
+    int column = int(constrain(x/resolution, 0, cols-1));
+    int row = int(constrain(y/resolution, 0, rows-1));
+    return field[column][row];
+  }
+
+  void drawField(float x, float y, PVector v) {
+    int column = int(constrain(x/resolution, 0, cols-1));
+    int row = int(constrain(y/resolution, 0, rows-1));
+    for (int i=-affectRadius; i<=affectRadius; i++) {
+      for (int j=-affectRadius; j<=affectRadius; j++) {
+        if (i*i+j*j<affectRadius*affectRadius) {
+          try { field[column+i][row+j] = v; }
+          catch(Exception e) {}
+        }
+      }
+    }
+  }
+
+  void onMouseDrag() {
+    PVector direc = new PVector(mouseX-pmouseX, mouseY-pmouseY).normalize();
+    drawField(pmouseX, pmouseY, direc);
+  }
+
+  void saveField() {
+    try {
+      FileWriter out = new FileWriter(file);
+      for (int i=0; i<cols; i++) {
+        for (int j=0; j<rows; j++) {
+          out.write(field[i][j].x+","+field[i][j].y+"\t");
+        }
+        out.write("\r\n");
+      }
+      out.close();
+    }
+    catch(Exception e) {}
+  }
+
+  void readField() throws IOException {
+    try {
+      BufferedReader in = new BufferedReader(new FileReader(file));
+      String line;
+      for (int i = 0; (line = in.readLine()) != null; i++) {
+        String[] temp = line.split("\t"); 
+        for (int j=0; j<temp.length; j++) {
+          String[] xy = temp[j].split(",");
+          float x = Float.parseFloat(xy[0]);
+          float y = Float.parseFloat(xy[1]);
+          field[i][j] = new PVector(x, y);
+        }
+      }
+      in.close();
+    }
+    catch(Exception e) {
+      throw new IOException("no field.txt");
+    }
+  }
+}

InteractiveStarryNight.pde

@@ -0,0 +1,100 @@
+final int STAGE_WIDTH = 1200;
+final int STAGE_HEIGHT = 950;
+final int NB_PARTICLES = 60000;
+final float MAX_PARTICLE_SPEED = 2.5;
+final float PARTICULE_SIZE = 2;
+final int MIN_LIFE_TIME = 10;
+final int MAX_LIFE_TIME = 20;
+final String IMAGE_PATH = "starrynight.jpg";
+myVector tabParticles[];
+PImage myImage;
+int imageW;
+int imageH;
+color myPixels[];
+FlowField ff;
+
+void setup()
+{
+  size(1200, 950, P3D);
+  background(0);
+  initializeImage();
+  initializeParticles();
+  ff = new FlowField(5);
+}
+
+void initializeImage()
+{
+  myImage = loadImage(IMAGE_PATH);
+  imageW = myImage.width;
+  imageH = myImage.height;
+  myPixels = new color[imageW * imageH];
+  myImage.loadPixels();
+  myPixels = myImage.pixels;
+  image(myImage, 0, 0);
+}
+
+void setParticle(int i) {
+  tabParticles[i] = new myVector((int)random(imageW), (int)random(imageH));
+  tabParticles[i].prevX = tabParticles[i].x;
+  tabParticles[i].prevY = tabParticles[i].y;
+  tabParticles[i].count = (int)random(MIN_LIFE_TIME, MAX_LIFE_TIME);
+  tabParticles[i].myColor = myPixels[(int)(tabParticles[i].y)*imageW + (int)(tabParticles[i].x)];
+}
+
+void initializeParticles()
+{
+  tabParticles = new myVector[NB_PARTICLES];
+  for (int i = 0; i < NB_PARTICLES; i++)
+  {
+    setParticle(i);
+  }
+}
+
+void draw()
+{
+  float vx;
+  float vy;
+  PVector v;
+  for (int i = 0; i < NB_PARTICLES; i++)
+  {
+    tabParticles[i].prevX = tabParticles[i].x;
+    tabParticles[i].prevY = tabParticles[i].y;
+    v = ff.lookup(tabParticles[i].x, tabParticles[i].y);
+    vx = v.x;
+    vy = v.y;
+    vx = constrain(vx, -MAX_PARTICLE_SPEED, MAX_PARTICLE_SPEED);
+    vy = constrain(vy, -MAX_PARTICLE_SPEED, MAX_PARTICLE_SPEED);
+    tabParticles[i].x += vx;
+    tabParticles[i].y += vy;
+    tabParticles[i].count--;
+    if ((tabParticles[i].x < 0) || (tabParticles[i].x > imageW-1) ||
+      (tabParticles[i].y < 0) || (tabParticles[i].y > imageH-1) ||
+      tabParticles[i].count < 0) {
+      setParticle(i);
+    }
+    strokeWeight(sqrt(vx*vx + vy*vy)*1.5*PARTICULE_SIZE);
+    stroke(tabParticles[i].myColor, 200);
+    line(tabParticles[i].prevX, tabParticles[i].prevY, tabParticles[i].x, tabParticles[i].y);
+  }
+}
+
+void mouseDragged() {
+  ff.onMouseDrag();
+}
+
+void keyPressed() {
+  if (key =='s' || key == 'S') {
+    //ff.saveField();
+  }
+}
+
+class myVector extends PVector
+{
+  myVector (float p_x, float p_y) {
+    super(p_x, p_y);
+  }
+  float prevX;
+  float prevY;
+  int count;
+  color myColor;
+}

README.md

@@ -1 +1,9 @@
-# InteractiveStarryNight
+# InteractiveStarryNight
+
+An interactive starry night implementation made with processing.
+
+You can draw your own flow field and press `S` to save your field.
+
+## 
+
+![](./starrynight.gif)